[74Grandville]

Originally Posted by Squidward

I used arp hardened washers under the nut to get set screw engagement.

X2, Some of the aftermarket balls have a built in height like a washer so a Polly lock can be used.

I originally bought 1.9” studs for mine, but found the set screw did not have enough engagement. I believe I went with normal BBC studs of 1.75” with arp washer on stock ball.

Roller rockers on HFT, 1.9 should work, but it also depends on your valve height.


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[pontiacmark]

All, so last night I mocked it up with stock rocker and pivot ball. The 1.75 in stud length is actually measured from under the hex to the tip of the thread. It is not the actual thread length. See attached picture. So when I measured the flat of the pivot ball to the tip of the stud, I came up with around 1.020 in. So I would think a nut that is 1.300 in should have plenty of length even after setting the pre-load. The only other concern would be if that would clear a stock valve cover.

[Cliff R]

It's not uncommon to have to jump thru some hoops when you get to this part of the engine assembly especially if you are trying to get all of it under stock valve covers.

I typically find myself shimming up the studs, or cutting down the locknuts for clearance, or getting longer studs and trimming them some if/as needed. The key is to make sure that you have at least 5 full turns with the locknuts when the valves are correctly adjusted.

All of this comes from many parts being "non-standard", plus decking/squaring, milling heads, different length valves, cam base circles, lifters, etc. Once you determine the correct pushrod length there may be some time required figuring out the stud length/lock nut required. It's easy if you have a lathe to cut things down if/as needed.

I've also corrected some set-up with using hardened load washers for shims, either under the studs or on top of the pivot balls as Lee mentioned. Not a big deal just make sure geometry is perfect, 5 full turns with the lock-nuts and that the valve covers sit on the gaskets and not on top of the locknuts........Cliff

[400 Lemans]

https://www.ebay.com/itm/Pontiac-sho...ox!28779!US!-1

Originally Posted by pontiacmark

All, so last night I mocked it up with stock rocker and pivot ball. The 1.75 in stud length is actually measured from under the hex to the tip of the thread. It is not the actual thread length. See attached picture. So when I measured the flat of the pivot ball to the tip of the stud, I came up with around 1.020 in. So I would think a nut that is 1.300 in should have plenty of length even after setting the pre-load. The only other concern would be if that would clear a stock valve cover.

Ordered these from Paul Spotts and they fit my stock rockers and stock valve covers with regular gaskets perfect.

[ponyakr]

Originally Posted by 400 Lemans

https://www.ebay.com/itm/Pontiac-sho...ox!28779!US!-1 Ordered these from Paul Spotts and they fit my stock rockers and stock valve covers with regular gaskets perfect.

The part number listed for those is a Comp Cams number. Jegs shows the CC 4606-16 nuts to be 1" long. No length is listed on that Ebay ad.

https://www.jegs.com/i/Comp+Cams/249...B&gclsrc=aw.ds

https://www.ebay.com/itm/Comp-Cams-H...EAAMXQjwVQ-1E6

So, please measure one & post the results here, so that the guys here will know their length, before ordering. With all the possible variables mentioned in this thread, it seems that you'd need to know the length of the nuts, BEFORE ordering.

There are 1/4" & 5/16" vc gaskets that might be needed for clearance, in some cases. And, some glue 2 gaskets together.

[pontiacmark]

As ponyakr said, there are a lot of variables. I am on a tight budget and trying to estimate total cost before I pull the trigger. The heads are done and sitting on my workbench. Just need to get cam/lifters and gaskets and perform the head and cam swap. THEN, pushrod and polylock length required will need to be checked before ordering.

Thanks all for the help. If I get this going soon I will feedback what all I did.